Vehicle for spreading pulverant material on a ground surface



H. H. TAKATA ET AL Aug. 27, 1968 3,398,662

VEHICLE FOR SPREADING PULVERANT MATERIAL ON A-GROUND SURFACE 4 Sheets-Sheet 1 Filed Feb. 27, 1967 km hm N w.

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VEHICLE FOR SPREADING PULVERANT MATERIAL ON A GROUND SURFACE Filed Feb. 27, 1967 4 Sheets-Sheet 2 FIE '5 drew/5 0. 41/44/4042 ,wrfaznb g- 1968 H. H. TAKATA ET AL 3,398,662

VEHICLE FOR SPREAD-ING PULVERANT MATERIAL ON A GROUND SURFACE Filed Feb. 27, 1967 4 Sheets-Sheet 5 v A Q, {3

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Aug. 27, 1968 H. H. TAKATA ET AL 3,398,662

VEHICLE FOR SPREADING PULVERANT MATERIAL ON A GROUND SURFACE Filed Feb. 27, 1967 4 Sheets-Sheet 4' FIG! 5 5' (2 7 62a in Kw gm as flrragwers United States Patent F 3,398,662 VEHICLE FOR SPREADING PULIERANT MATERIAL ON A GROUND SURFACE Harry H. Takata and William D. Tuggle, Golden Valley,

and Archie 0. Williamson, Edina, Minn., assignors to Bros Incorporated, Minneapolis, Minn., a corporation of Minnesota Filed Feb. 27, 1967, Ser. No. 618,896 11 Claims. (Cl. 94-69) ABSTRACT OF THE DISCLOSURE A self-propelled vehicle for spreading portland cement or the like upon a ground surface through means of a plurality of angers extending longitudinally along the bottom of a vehicle carried cement hopper or body to a discharge chute. The rotational speed of the angers has direct ratio to the ground traction wheel speed but this ratio can be selectively varied by the operator. The spreader hopper or body has an air inlet or inlets and an air outlet with a filter interposed therebetween for pneumatic loading and has a collection hood adjacent the discharge chute for returning airborne particles to the hopper.

This invention relates generally to machines for spreading a pulverant material over the ground and more particularly concerns such machines as are adapted to travel over the ground surface and dispense a layer of binder material, such as portland cement, upon the ground soil to be later mixed therewith the stabilize the same into a hard layer for use as a roadway, airstrip or the like.

One form of soil stabilization is the process of intermixing a binder and Water with soil to harden and strengthen the same. This is being used with increasing effectiveness in roads, airstrips, roadway shoulders, parking areas and the like. Generally the soil is stabilized to provide a solid base course which is subsequently covered by a bituminous course or some other form of wear course. Salt, calcium chloride, lime or other pulverant materials may be used as a binder for stabilizing soil to be used for roadways or other areas intended to carry a rather heavy surface weight. This process is generally referred to as soil stabilization.

As an example in carrying out a soil-cement stabilization process, to build a base course for a roadway, the following steps are usually undertaken. First, the roadway is shaped, crowned and graded with the existing materials which may be gravel, sand, slit, clay, shale or a mixture of the same. Borrow soil may, of course, be added v where necessary. Then a layer of portland cement (with the thickness depending upon the soil material) is spread over the entire area to be stabilized. Thirdly, the cement, soil and water are mixed by suitable ground penetrating equipment. The area is then compacted. As the cement hydrates the mixture hardens providing a strong base course which will not further consolidate or rut under trafiic loads. A finish course of bituminous pavement or the like is generally applied to the stabilized course to prevent flaking or erosion of the 'base course. The stabilized base course is normally four to eight inches thick dependent upon the anticipated traffic load.

The present invention is concerned with the second step in the process set forth above, namely, the spreading of cement in a uniform layer upon the pregraded soil. This has previously been accomplished by various means such as laying windrows from a bulk tanker and the spreading the cement laterally from the windrow, or by dispensation from the rear end of a truck vehicle or a spreading machine connected in draft relation to a cement bulker.

The primary object of the present invention is to pro- 3,398,662 Patented Aug. 27, 1968 vide a new and improved vehicle for use in soil stabilization and adapted to carry cement or like binder material and spread such material in an even layer over the area of soil to be stabilized regardless of variations in vehicle speed.

Another object of the invention is to provide a machine for spreading cement or other small particle pulverant material in a layer upon a ground surface and wherein the material is loaded into the machine pneumatically and having an improved means for separating the material in the machine from the conveying air stream.

Still another object of the invention is to provide a machine for spreading cement or other small particled material upon a ground surface and having means for collecting airborne material portions after discharge from the machine.

Still another object of the invention is to provide a machine for spreading a layer of cement or other small particle material upon the ground surface and having means for adjusting the width of the layer deposited thereon.

Still another object of the invention is to provide a machine for spreading a layer of cement or other small particle material upon a ground surface by means of screw conveyors and having means for adjusting the speed of the conveyors relative to the ground speed of the spreader whereby the rate of pulverant material delivery per distance traveled may be varied.

The above mentioned and other objects of the invention will be brought to light during the course of the following specification, reference being made to the accompanying drawings, in which FIG. 1 is a side elevation of our novel pulverant spreader arranged in tandem relation behind a conventional pulverant bulker truck.

FIG. 2 is a plan view of the spreader with the hopper cover partially broken away to show the interior thereof and with the rear hopper wall further broken away to show the screw conveyors disposed thereunder.

FIG. 3 is a side elevation of the spreader with the left side wall thereof partially broken away to show the hopper interior and a portion of the drive train to the ground wheels.

FIG. 4 is an enlarged longitudinal vertical section through the spreader body taken on line 44 of FIG. 2 with arrows denoting the direction of cement flow through the spreader and showing the drive train to the screw conveyors.

FIG. 5 is a rear elevation of the lower and central portion of the spreader.

FIG. 6 is a vertical section taken on line 66 of FIG. 5.

Referring now more particularly to the drawlngs reference characters will be used to denote like parts or structural features in the different views. A conventional portland cement bulker is denoted generally by the numeral 10 in FIG. 1. This comprises a motive tractor unit 11 and a bulk tank trailer unit 12 having its forward end pivoted to the tractor unit and its rear portion supported on ground wheels 14. The unit '12 is designed to carry a quantity of cement or like pulverant material which may be emptied therefrom through the bottom troughs 15 and line 16 under action of the blower 17 and into the discharge line 18.

The pulverant spreader forming the subject matter of this invention is denoted generally by the numeral 20. This is a self-propelled vehicle having a main frame 21 supported upon steerable front wheels 22 and rear traction wheels 24. Above the wheels 22 the frame 21 has an operators platform 25 mounted thereon which carries an operators seat 26 to the rear of a steering wheel 27 which is suitably connected to the wheels 22 for turning the same. The vehicle engine 28 has a driving con- 3 I nection with ground wheels 24 (FIG. 3) through a torque converter 28 the transmission 30, drive shaft 31 and suitable differential and axle assembly 32 (FIG. 4) disposed -between the wheels 24.

The pulverant hopper mounted on frame 21 is denoted generally by the numeral 34. This hopper is actually a tank-like enclosure having side walls 35 (FIG. 2.), front and rear walls denoted at 36 and 37 respectively, and a top wall 38. The lower portion of the front wall 36 angles rearwardly as at 39 and then downwardly as at .40 (FIG. 4). The lower portion of the rear wall 37 angles forwardly in its downward extension as at 41.

The bottom of the hopper 34 extends across the entire width thereof and is formed with a series of side by side longitudinally extending upwardly opening arcuate auger channels 44. In the form of the invention shown here there are fourteen of said channels. Above the channels 44 and extending crosswise across the hopper 34 are three triangular-shaped partitions 45 which in combination with the front and rear walls 39 and 41 divide the lower portion of the hopper into four transverse downwardly tapering troughs 46 which open at their lower ends into the auger channels 44.

An elongated auger or screw conveyor 48 extends longitudinally along each channel 44. Each conveyor has a tubular shaft 49 having its forward end suitably journaled in wall 40 as at 50 and a spiral vane 51 encircling the shaft and having an external diameter mating with the inner diameter of the channel. Channels 44 extend rearwardly beyond the rearrnost transverse trough 46 into a tunnel 52 having a roof 53 formed with downwardly opening channel sections conforming to the upper half of the auger vanes.

The rear end portion of tunnel 52 opens downwardly into a chute 55 extending transversely across the entire width of the hopper 34. This chute has a front wall 56 and a rear wall 57 and is divided into fourteen separate passageways, one aligned with each auger 48, by means of transversely spaced partitions 58 (FIG. 5). The lower end of chute 55 opens downwardly as at 59 in spaced relation above the ground. Angers 48 extend rearwardly through tunnel 52 into the upper portion of chute 55 with the rear end of each shaft 49 connected to an extension 59* which is journaled in Wall 57 as by bearing assembly 60 (FIG. 6) and which extends rearwardly therebeyond.

Each shaft extension 59 has a rear end portion 61 on which there is journaled a gear 62. Each gear 62 is in intermeshing engagement with the gears 62 at each side thereof, at best shown in FIG. 5. To the rear of each gear 62 and mounted on shaft portion 61 is a hand operated clutch mechanism 64 controlled by a handle 65. The purpose of clutch 64 is to engage or disengage gear 62 with the shaft extension 59*. In normal use the gear and shaft are in driving engagement. One of the central gears 62, denoted at 62 in FIG. 5, is the driving gear. This gear 62 is secured in axial alignment to a sprocket 67 which is journaled on a hub 68 mounted on wall 57 (FIG. 6). Sprocket 67 is connected as by sprocket chain 69 with a sprocket 70 mounted on the rear end of drive shaft 71. Shaft 71 extends forwardly through chute 55 under the hopper floor 44 and carries a sprocket 72 at its forward end. This sprocket 72 meshes with a sprocket 74 mounted on the output shaft of a positive infinite variable speed transmission (PIV) 75 which has its input shaft 76 in driven connection at 77 with the engine driven jack shaft 29 to be subsequently described.

The screw conveyor drive will now be understood flowing from the engine 28 through shaft 29, PIV 75 and drive shaft 71 to the sprocket 67 and gear 62 Inasmuch as all of the gears 62 are of the same diameter and are in meshing engagement, either directly or through other gears 62 with the gear 62*, all of the gears 62 will be constantly rotated at a uniform speed. It will be appreciated that next adjacent gears 62 will be rotated in opposite directions' and for this reason the auger flights 51 on next adjacent screw conveyors will. be reversed so that all of them will convey in a rearward direction.

A tightener pulley 78 (FIG. 5) on bracket 79 is mounted on the chute rear wall 57 for engagement with the sprocket chain 69.

As hereinbefore stated the pulverant material C is pneumatically conveyed into the hopper 34 through the line 18. It is then necessary to separate the material from the conveying air. This is accomplished by the filter designated generally at 80 and best shown in FIG, 4.'This filter is mounted in the upper portion of the hopper 34, preferably on the left' side or the side opposite from the connection of line 18 with the hopper. The filter is of a known commercial type comprising a series of filter bags 81 mounted in parallelism. Each bag comprises a rectangular support frame covered with an upwardly opening bag or envelope of suitable fabric filtering material. The conveying air flows upwardly between and through the bags 81 discharging into the compartment 82 from which it is vented to atmosphere through the openings 84 (FIG. 3) in the hopper roof 38. As the air passes through the fabric bags 81 the pulverant materials will be retained on the surface and interstices of the fabric strands building up a filter cake that itself acts as a filter medium. This filter cake must be dislodged periodically so as not to materially resist the air flow and the conveying rate.

The cleaning of the filter is accomplished by the shaker mechanism disposed therebelow. This comprises a rod 86 having its rear end journaled in a support member 87 and its forward end journaled in front wall 36 and carrying a crank handle '88 which is disposed just to the rear of the operators seat 26. The rod 86 has integral cross plates 89 thereon which jointly support a pair of filter bag contact rods 90 one on each side of rod 86. As the operator oscillates the crank 88, the shaker frame will rock with rods 90 hitting opposite bottom portions of the bags 81 to dislodge the filter cake therefrom into the hopper body.

A dust collection hood 92 (FIGS. 3 and 5) is mounted on the rear wall 57 of the chute 55. This hood opens downwardly as at 93 just to the rear of the chute and across the entire width thereof. The top walls of the hood, as shown in FIG. 5, make connection with the lower end of a conduit 94 which has its upper end connected to a blower 95. A dustreturn conduit 96 connects the blower 95 to the hopper 34 at a place above the level of cement material C.

The power means for driving blower 95 is not shown. Preferably, however, there is a hydraulic pump mounted at the side of engine 28 and driven thereby. This pump is connected by pressure and return lines extending rearwardly along the right side of the hopper 34 to a hydraulic motor mounted coaxially with and on the right side of blower 95 and having a driving connection therewith, all as is well known in the art.

It may be desirable to use some form of agitation means in troughs 46, such as a positive air flow into the bed, to assure continuous movement of the material into the conveyor channels.

In operation the spreader 20 may be driven in tandem relation with the bulker 10 as shown in FIG. 1. When so used there will be a continuous flow of the cement material through lines 16 and 18 to the hopper 34. The material will churn around in the hopper 34 and gradually settle into the bed thereof as the conveying air passes out through the filter 80. As this takes place the material in the troughs 46 will descend into the screw conveyor channels and will be moved rearwardly by the conveyors 48 into the chute 55 which discharges the material onto the ground. There will be a certain amount of the material in the form of airborne dust which will not fall upon the ground through opening 59. This dust will be collected in the hood 92 and returned by blower 95 through pipes 94 and 96 to the hopper 34. This pneumatic collection is possible due to the use of filter 80 as a separatorrather than a cyclone separator or the like.

- :In the alternative the spreader may be loaded from the bulker or other source at a selected loading point and then driven to and over the areawhere the cement is to be spread. It is also conceivable that the hopper be provided with double inlets for connec'tion'with two separate bulker discharge lines 18 for faster loading.

In certain instances it might be desirable to discharge the cement material in a stream narrower than the entire width of the machine. In such an event the drive to any desired group of conveyorsmay be cut off by disengaging the clutches 64 thereof through operation of the handles. For example, if a stream of only half of the full width is desired, the seven conveyors at the right side or at the left side of the machine may be shut off by disengaging the clutches thereof. It will be understood that all of the gears 62 will continue to rotate.

It might also be desirable to use only alternate conveyors to deposit a thinner layer of material upon the ground. In such case alternate clutches 64 are disengaged so that approximately half as much cement will be deposited over approximately the same area.

However, the preferred means of varying the rate of delivery per distance of travel is through the variable speed transmission 75. This is a commercially available Link Belt PIV having an overall range of approximately 6 to 1.

Referring to FIG. 4 it will be observed that the drive train from the torque converter 28 to the PIV 75 includes a clutch 102 on jack shaft 29 journaled on frame 21. Shaft 29 has a sprocket 103 mounted thereon which is connected by chain 77 with a sprocket 104 on the input shaft of the PIV 75. Clutch 102 is engaged or disengaged by operation of control 100, adjacent to the operators seat, which is connected to the clutch by rod 101. It will accordingly be understood that the operator may selectively connect or disconnect the drive to conveyors 48 by opera tion of control 100.

The output shaft of the torque converter 28*, when clutch 102 is engaged, is connected to both the input of the PIV transmission 75 and the drive transmission 30 with the result that the rotational speed of the angers 48 has a direct and constant ratio to the ground speed of wheels 24. This assures the deposit of a uniform material layer in spite of variations in the vehicle speed. The above mentioned ratio may be selectively varied, however, by adjusting the PIV output speed. This PIV adjustment is accomplished through operation of a crank 108 mounted at the operators station (FIG. 3) which carries a sprocket 109 at its forward end. This sprocket 109 is connected by sprocket chain 110 to a sprocket 111 mounted at the forward end of an elongated shaft 112 which has its rear end in operative connection with the variable control shaft on the PIV which adjusts the output speed thereof relative to the input speed. A gauge 115 is mounted at the operators station and has an indicator needle operated by suitable gearing on crank 108 to denote the input-output adjustment of the PIV 75.

A relief valve is provided on the hopper in the form of an opening 119 in the top wall 38 thereof covered by a metal gate 120 hinged as at 121 to the wall. Excessive pressure in the tank will raise the gate to allow the escape of air.

Windows may be provided on the side walls 35 of the hopper so that the operator might observe the cementlevel therein. In the remote event that any of the conveyors become jammed, they may be disconnected at 50 and hub 60 detached for rearward withdrawal of the entire conveyor.

'I'he spreader accordingly effectively carries out the aforementioned objectives. It is understood that suitable modifications may be made in the structure as disclosed,

6 provided such modifications come within the spirit and scope of the appended claims. Having nOW therefore fully illustrated and described our invention, what we claim to be new and desire to protect by Letters Patent is:

We claim:

1. In a vehicle for dispensing pulverant material upon a ground surface, a frame having at least one traction ground wheel and at least one steerable wheel mounted thereon, an operators station on the frame having a steering means operably connected to the steerable wheel, a power unit on the frame having a driving connection with the traction ground wheel, a hopper on the frame for holding a quantity of pulverant material, a discharge chute extending transversely across the rear end of the frame, a plurality of screw conveyors extending in parallelism longitudinally along the bottom of the hopper with the rear end portions thereof extending to the upper portion of the chute, and adapted to convey material from the bottom portion of the hopper into the chute for discharge therethrough onto the ground surface, drive means connecting the power unit to the screw conveyors, and said chute having a plurality of transversely spaced vertical partitions dividing the chute into a plurality of vertical passageways.

2. The subject matter of claim 1 wherein the drive means between the power unit and conveyors incorporates individually operative clutch means for each conveyor screw whereby the drive to each screw may be independently engaged or disengaged.

3. The subject matter of claim 2 wherein said drive means includes a plurality of interconnected positive drive mechanisms rotatably mounted one on each conveyor, and said clutch means comprising individual clutches mounted on each conveyor for rotatably locking or releasing the drive mechanism on said conveyor, and means for independently engaging and disengaging said clutches.

4. The subject matter of claim 1 wherein the hopper is enclosed and is provided with at least one inlet for pneumatic reception of the material and an air outlet for discharge of air, and a filtering device interposed between the inlet and outlet comprising a series of bags of perforate material having a large surface which is porous to air passage but adapted to collect material particles thereon.

5. The subject matter of claim 1 wherein the hopper is provided with a filter covered air discharge outlet and an airborne collection hood opening downwardly adjacent to the discharge chute, conduit means connecting the hood to the upper portion of the hopper, and a blower mounted in the conduit means to create a suction in the hood to collect airborne particles discharging from the chute and return them tothe hopper.

6. The subject matter of claim 4 wherein the hopper is provided with a relief valve adapted to release excess pressure in the hopper.

7. The subject matter of claim 1 wherein said drive means includes a variable speed transmission for varying the speed of the conveyors to vary the amount of material discharged thereby over a given distance of travel, and control means operable from the operators station for controlling the speed of said transmission.

8. In a vehicle for dispensing pulverant material upon a ground surface, a hopper for holding the material, said hopper being provided with an air discharge outlet having filtering means thereover, a discharge spout on the hopper, means for discharging the material from the hopper through the discharge spout in a layer on the ground surface as the vehicle moves thereover, an airborne material collection hood opening downwardly adjacent to the discharge spout, conduit means connecting the hood to the hopper, and a blower mounted in the conduit means to create a suction in the hood whereby airborne material particles leaving the spout will be collected in the hood and returned to the hopper in an air stream created by the blower with the air in said stream passing out of the hopper through said discharge outlet.

9. The subject matter of claim 8 wherein the discharge spout and hood each extends transversely across the entire width of the vehicle.

10. In a vehicle for dispensing pulverant material upon a ground surface, a frame having at least one traction ground wheel mounted thereon, a power unit on the frame, a first drive means connecting the power unit to the ground wheel, a hopper on the frame for holding a quantity of pulverant material,- a discharge chute extending transversely across the rear end of the frame, a plu rality of screw conveyors extending in parallelism longitudinally along the bottom of the hopper and adapted to convey material from the hopper rearwardly into the chute for discharge therethrough onto the ground surface, a second drive means connecting the power unit to the conveyors to rotate the same, said first and second drive means powered through a common transmission whereby the rotational speed of the conveyors has a direct ratio to the ground wheel speed for' discharge of a uniform layer of material upon the ground.

11. The subject matter of claim 10 wherein said second drive means includes a variable speed transmission, :and control means for adjusting the output speed thereofrto selectively vary said ratio.

References Cited 1,

NILE c. BYERS, 111., Primdry'Examiner. 

